Millstock purifier



Uclt. M 1mm 15mm H. VKLM MILLSTOCK PURIFIER- Filed Avril 26, 1922 2 Sheets-Sheet 1 c1 11. 121., v 1 1,511,119 V H. VILM MILL$TOCK RURIFIER Filed Avril 26 192.2 2 Sheets-Sheet 2 Patented Uet. l l, T924.

HENRY VILM, OF KANfiAS CITY, MISSOURI.

MILLSTOCK runrrinn.

Application filed April 26, 1922.

To all whom it may concern Be it known that T, HENRY VILM, acitizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Millstock Purifiers; and I do declare'the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

This invention relates to purifiers and particularly to a gravity and r turn air purifier for mill stock in flour mills. v

The primary object is to provide an improved purifier which will separate and grade materials of different specific gravities, the material especially contemplated being known as middlings.

- Novel means is provided for separating the lighter particles from the heavierparticles, allowing the heavier particles to gravitate into chambers or bins to be subsequently carried ed to reduction rolls, bolters or other appropriate machines.

Means is also provided for maintaining a substantially closed air'circulation so that the air may be used continuously; there being means provided, however, to augment the supply to take care of whatever leaks occur. i

There is a special advantage in using the air repeatedly because after the air ha taken up a certain amount of moisture, it will not absorb any more moisture from the mill stock whereas if a continuous circula tion of air is maintained through the machine, that is, if air is taken in at one end of the machine and exhausted at theother, not only will there be a considerable loss in heat but the incoming fresh air will absorb a considerable amount of moisture in the stock and cause it to become brittle, thereby increasing the amount of ash over that which would be present where a closed, recurring air circuit is used.

Another important featureof the invention, over similar devices which have oscillating or vibrating parts is that the liability of flouring due to attrition in passing through purifiers will be materially reduced.

Serial No. 556,592.

In actual practice I have found that the attrition losses are not appreciable in my device, whereas they are quite a factor in devices which agitate the stock so that the particles rub one against the other and cause flouring or ash.

The novel construction of the invention as wellas the manifold advantages will be apparent by reference to the following description, reference bein had to the accompanyin drawings, in which- 7 T ig. l is a perspective view of a purifier constructed in accordancewith my invention.

Fig. 2 is a vertical, longitudinal, sectional view through the purifier, the air conduit from the air impeller being shown in elevation, and

Fig. 8 is a sectional view of the discharge conveyor and the upper end of the chute with which it communicates.

The purifier is shown as comprising an approximately rectangular hollow casing, divided into a plurality of separation chambers 1, 2, 3, a and 5 respectively. The casing is generically designated 6 and the bottom orfioor thereof is divided into the hoppers or separation chambers 5, 1, 2 and 3 in the order named. The respective chambers 5, 1, 2 and 3 are provided with valved outlets 7, 8, 9 audit! in the vertexes of the hoppers. The valves are shown as consisting of rotatable cylinders 11, having radial wings or blades 12, providing pockets 13 to feed the material into the respective chutes 14, 15, 16 and 17, which may lead to the reducing rolls, bolters or other appropriate machines.

Dividing the hopper 5 from the hopper 1 is an upstanding rigid baflie 18; the hopper l is divided from the hopper 2 by a hinged baffle 19; the hopper 2 is divided from the hopper 3 by a hinged u standing baflle 20 corresponding to the ba e 19 and the baffles 19 and 20 are adapted to be swung on their hinges from the exterior of the machine by the crank arms 21 and 22 fixed to the shafts 28 and 24C of the respective bafiles 19 and 20 so that the angles of inclination of the bafiies 19 and 20 may be varied.

At the top of the machine is a feed hopper 25, which receives the stock from any suitable source, preferably a chute or conveyor. One side of the hopper 25 is provided with a hinged wall 26, provided with weights 27 i I so that the wall or gate'26 will normallylie against the corrugatedfeed roll 28 extendlng ;T-he chute Or'bOaI'd 29 is provided at its [lower end With-anupturned dischargeplate 30," which terminatesadjacent to and below the upper edge of the baffle or wall19 so that when the stock is fed by the roller 28 onto the board 29 and slides overthe surface thereof, it will acquire sufiicient velocity to be directed upwardly and over the upper edge of the hinged 'valve plate 80- of the hopper 19, bridgingthe gap 31 betweenthef plate 30 and the baflie 19, allowing the air to 'carrythe lighterxparticles into the hopper 2,

the. heavier particles, gravitating into the receptacle orqh pper 1..I V I In other words,.the air will lighter particles beyond the gap 31 and into the,hopper 2. The lighter particles will strike the depending baffle board or wall 32 interposed between the baflles 19 and 20 and be rdirectedin anopposite direction to said ;baffles so as to: form a tortuous passage" as (indicated by the arrows, Y

-The air' will pass down below the lower edge of the baflle 32 andover the baffle 20,

7 allowing the heavier'particles passing be-- tween lgand 20 t d op into the hopper 2 but. carrying the lighter-particles over the 7 ba'liie 20"into the hopper 3; I c

The current of" air then; {passes up through-the superposed hopper, 33 above the hopper 3," which enclosesvtheseparation -;chamber 4, the .entrance' being through the valved opening 34. .In doing this, itcar ries 'withit the particles which are too light togravitate-into the hopper 3 and'most of *them .Wlll gravitate to the bottomlof the -ofthehopper' 33 andthatit' communicates hopper 33 and be carried by the screw con veyor 35 to the chute 136.:

,B reference to Fig, 2a will be obese that the impeller; or'fan 37 is at the top withthe-chamber; 4' through 'a side inlet 38. The fan-will cause a slight vacuum to be "formed in the chamber 4"to' draw the lighter particles'thereinto and some of the finest particles will pass into the fan 37' and be" forced by the impeller 39 through the return conduit 40 into the space 41, above the hopper 5, where the solids will strike against the bafile18 and causethe finest '7 particles to drop into the hopper 5 to be discharged into the conveyor "14 .so that practically air'only will enter beneath the board 29 into the hopper 1,to act upon the 7 stock discharged from the plate 30'. 1 r-The gate42, covering the opening 34, is

V j a deflector; plate, tending to direct p the t major portion of the finer particles enter-- 7 65' mg the chamber 4 onto the, conveyor 35, it

only carry the 1 being understood that only the very finest particles are sucked into the fan 37 to be discharged into the hopper 5.

- It will be apparent that a continuous, recurrin circulation of the same air will take place t irough the casing 6.

All of the parts are so mounted that therewill be very little leakage but, obviously, it will be impossible to entirely eliminate leakage of air in any machine having operating parts, so in order to augment the supply of air, I have provided at the dome portion 43 constituting the roof of the chamber 4, an inlet consisting .of an upstanding perforate tube'44, having a sleeved cap '45 fitting over the same so that the effective port area of, the air inlet tube can be controlled ;to allow only enough air'to enter the casing 6 as is necessary to compensate for the amount of leakage.

' The air" impeller may be driven from a belt 46, passing around a pulley 47 on the shaft 48, the belt being shown as also passing over a pulley 49 on a shaft 50, driven by a belt 51, which passes over a pulley 52 thereon; The end of the shaft distant from the one carrying the pulle 49, carries a pulley 53, which drives a be t 54 passing around a pulley 55 on the shaft 56 for the roller 28, so that the feed roller 28 will be constantly driven during the time that the fan is driven and the shaft 50 also carries a pulley 57, which drives a pulley 58 on the shaft 59 through the medium of the belt, 60. The shaft 58 carriespinions 61, which meshwith beveled gears 62 on the ends of the valve cylinders 11 for the respective hoppers 5, 1, 2 and 3 so that the valves 11 will be constantly rotated to feed the materials from the hoppers into the chutes 14, 15, 16 and 17. 1

in order to externally control the gate '42 I have provided a crank arm 63 on the end of theshaft'64 for the deflector valve or gate 42.

The screw conveyor 35 is-provided with a shaft 65, which extends through oneside of the machine and which is provided with a pulley 66 driven from the pulley 67 on shaft 48 through themedium of a belt 68.

When the parts are assembled and the machine is operating, mill stock will be fed into the hopper 25, the rate being controlled by the weighted gate 26 and the rotating feed roller 28. As it gravitates down the inclined chute or board 29, it will be directed upwardly toward, the upper edge of the bafile 19,; the air discharging from the conduit 40,

constituting the discharge end of the fan,

will pass through the chamber 41, l over 18 and up through the gap 31, carrying the lighter particles into the hopper or chamber '2 and allowing the heavier particles to gravitate into the hopper or chamber 1, the lighter particles being progressively separated in the chambers 0r hoppers 2, 3 and 4 and finally the lightest particles Will be deposited in the chamber 5, as will be apparent from the foregoing description.

The proportion of the flow passing from the plate 30 to the upper edge of the baffle 19 can be controlled by swinging the hopper 9 on its hinge; that is, if the size of the gap 81 is increased, a greater percentage of the stock will be permitted to gravitate into the hopper 1 than would be possible if the gap were narrowed. The same is true with respect to the baffle 20 and the positions of these bafiles can be conveniently controlled through means of the crank arms 21 and 22.

On the chute 36 is a spring-pressed valve 69 which tends to close the outlet 7 0 for the conveyor so as to prevent leakage into the machine. The valve 69, however, will open under the action of the material discharged by the conveyor 35 but the valve will only open enough to allow the discharge of the flour. Therefore, the discharge end 70 is practically sealed at alltimes because the flour, piling up at the exit end of the discharge 70, will, in itself, act as an air seal.

From the foregoing it will be apparent that with the construction of purifier contemplated by my invention the heavier particles of stock can be inversely separated from the heaviest to the lightest, over a range dependent upon the number and arrangement of the hoppers, and that the pro- Mt portion of the stream of material to be received in any one hopper can be controlled by arranging the positions of the baffles. It will also be observed that the air can be repeatedly used so as to maintain the necessary moisture in the stock and without liability of drying it out during the separation operation, it being only necessary to add such amounts of air as are required to 001m pensate for natural losses due to leakage,

which is bound to occur in any machine in which there are movable parts.

What I claim and desire to secure by Letters-Patent is:

A device of the class described comprising a closed casing, a plurality of communicating separating chambers in the bottom of the casing having open upper ends, means for feeding mill stock into the space above the second chamber, means for feeding air into the first chamber, means for directing air from the first chamber into the second chamber to permit it to pass therethrough into a third chamber, means for directing air from the third chamber into a fourth chamber, and means for returning some of the mill stock from the fourth chamber to the first chamber, said means comprising a chamber located above the fourth chamber and having an inlet to one side thereof and a return conduit having an air impeller therein, the return conduit leading from the last mentioned chamber to the first chamber, and discharging into the top thereof.

In testimony whereof I aflix my signature.

HENRY VILM. 

